This invention relates to devices for preventing the connection or disconnection of an electronic module from an electrical unit unless the power switch is off. The invention represents an improvement over U.S. patent application Ser. No. 07/065,233, filed June 22, 1987, now U.S. Pat. No. 4,777,332, the disclosure of which is incorporated by reference.
Many electrical units have subassemblies or modules which can be removed from and mounted to the unit. When removed and replaced, mating electrical connectors on the unit and module disconnect and connect. This typically occurs when the module is fully mounted within the unit through the use of blind mateable connectors. That is, electrical connection is made during the final movement of the electronic module into the electrical unit while electrical disconnection is made during the initial movement of the electronic module from the electrical unit.
When using such modules it is important that the power to the electronic module be off when it is removed or replaced. This is necessary to prevent possible damage to the equipment due to high transient voltages which can be created when a live electrical connector is manually disconnected or connected. This problem has been recognized in the art. See, for example, U.S. Pat. No. 3,919,507 to Middleton Jr., dated Nov. 11, 1975.